All good points.
Another thing I've found with vamps is we have like 3 sorts of units. Most of which aren't the same as other armies. We really don't have anvils or hammers(Crypt Horrors aside) etc. I find what we have is:
1.Chaff (like most armies), consisting of wolves, bats, raise dead zombies etc
2.Tarpits, not to be confused with anvils. Tarpits are there to just lock up enemy units and try not to die to quickly, never relied upon to do anything, so skellies and zombies.
3.Bullies. Our bullies are our heavy hitters that most people would call hammers, used in conjunction with anvils. Seeing as we don't have good anvils (due to crumble) we only have bullies. They way I'd say they work is hitting units that are far beneath them so they can easily win. An excellent example of a bully is a blender lord, we never try to put him up against opponents characters, he is there purely to bully the hell out of poor old RnF troops..
We obviously chaff as per usual, but instead of setting up hammer/anvils, you just gum up the opponents good stuff with zombies and skeles then let the bullies run around taking off the (hopefully) inferior units that are not in combat (as the opponent has tried getting his heavy hitters in quick). Obviously mileage will vary depending on armies played.
But what I'm getting at long windedly is I find blood knights as fantastic bullies, just not good Hammers and I also don't believe they should be compared to black knights as they play completely different roles. One is a bully and should be hitting weak targets, the other is an elite tarpit/delivery system like skeletons but faster. They play different roles. One wouldn't compare varghiests and crypt horros would they? as they again play different roles.
Also as a matter of tactics, run blood knights with a varghulf. Varghulf goes in the front and tries to draw with static combat res (get a couple of wounds and thunderstonp to negate ranks and banner etc) get the bloods (or vargs) in the side for the sweet sweet gravy...
Cheers,
TheTrans